We study new decision and optimization problems of finding a simple path between two given vertices in an arc weighted directed multigraph such that the path length is equal to a given number or it does not fall into the given forbidden intervals (gaps). A fairly complete computational complexity classification is provided and exact and approximation algorithms are suggested.

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We study new decision and optimization problems of finding a simple path between two given vertices in an arc weighted directed multigraph such that the path length is equal to a given number or it does not fall into the given forbidden intervals (gaps). A fairly complete computational complexity classification is provided and exact and approximation algorithms are suggested.
http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21783Mean residual life of coherent systems consisting of multiple types of dependent componentshttp://feedproxy.google.com/~r/wileyonlinelibrary/nav/~3/IjT5QPXd0dA/doiMean residual life of coherent systems consisting of multiple types of dependent componentsSerkan Eryilmaz, Frank P.A. Coolen, Tahani Coolen-Maturi2018-03-07T10:32:44.763332-05:00doi:10.1002/nav.21782John Wiley & Sons, Inc.10.1002/nav.21782http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21782RESEARCH ARTICLEn/an/aAbstract

Mean residual life is a useful dynamic characteristic to study reliability of a system. It has been widely considered in the literature not only for single unit systems but also for coherent systems. This article is concerned with the study of mean residual life for a coherent system that consists of multiple types of dependent components. In particular, the survival signature based generalized mixture representation is obtained for the survival function of a coherent system and it is used to evaluate the mean residual life function. Furthermore, two mean residual life functions under different conditional events on components’ lifetimes are also defined and studied.

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Mean residual life is a useful dynamic characteristic to study reliability of a system. It has been widely considered in the literature not only for single unit systems but also for coherent systems. This article is concerned with the study of mean residual life for a coherent system that consists of multiple types of dependent components. In particular, the survival signature based generalized mixture representation is obtained for the survival function of a coherent system and it is used to evaluate the mean residual life function. Furthermore, two mean residual life functions under different conditional events on components’ lifetimes are also defined and studied.
http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21782On the convergence of optimal actions for Markov decision processes and the optimality of (s, S) inventory policieshttp://feedproxy.google.com/~r/wileyonlinelibrary/nav/~3/bV6KyXq-5Do/doiOn the convergence of optimal actions for Markov decision processes and the optimality of (s, S) inventory policiesEugene A. Feinberg, Mark E. Lewis2017-08-11T20:46:25.106992-05:00doi:10.1002/nav.21750John Wiley & Sons, Inc.10.1002/nav.21750http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21750Research Articlen/an/aAbstract

We propose a novel simulation-based approach for solving two-stage stochastic programs with recourse and endogenous (decision dependent) uncertainty. The proposed augmented nested sampling approach recasts the stochastic optimization problem as a simulation problem by treating the decision variables as random. The optimal decision is obtained via the mode of the augmented probability model. We illustrate our methodology on a newsvendor problem with stock-dependent uncertain demand both in single and multi-item (news-stand) cases. We provide performance comparisons with Markov chain Monte Carlo and traditional Monte Carlo simulation-based optimization schemes. Finally, we conclude with directions for future research.

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We propose a novel simulation-based approach for solving two-stage stochastic programs with recourse and endogenous (decision dependent) uncertainty. The proposed augmented nested sampling approach recasts the stochastic optimization problem as a simulation problem by treating the decision variables as random. The optimal decision is obtained via the mode of the augmented probability model. We illustrate our methodology on a newsvendor problem with stock-dependent uncertain demand both in single and multi-item (news-stand) cases. We provide performance comparisons with Markov chain Monte Carlo and traditional Monte Carlo simulation-based optimization schemes. Finally, we conclude with directions for future research.
http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21778Two-agent scheduling on a single sequential and compatible batching machinehttp://feedproxy.google.com/~r/wileyonlinelibrary/nav/~3/Me8RRZY-X90/doiTwo-agent scheduling on a single sequential and compatible batching machineShisheng Li, T.C.E. Cheng, C.T. Ng, Jinjiang Yuan2018-02-02T12:00:43.804638-05:00doi:10.1002/nav.21779John Wiley & Sons, Inc.10.1002/nav.21779http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21779RESEARCH ARTICLE628641Abstract

We study two-agent scheduling on a single sequential and compatible batching machine in which jobs in each batch are processed sequentially and compatibility means that jobs of distinct agents can be processed in a common batch. A fixed setup time is required before each batch is started. Each agent seeks to optimize some scheduling criterion that depends on the completion times of its own jobs only. We consider several scheduling problems arising from different combinations of some regular scheduling criteria, including the maximum cost (embracing lateness and makespan as its special cases), the total completion time, and the (weighted) number of tardy jobs. Our goal is to find an optimal schedule that minimizes the objective value of one agent, subject to an upper bound on the objective value of the other agent. For each problem under consideration, we provide either a polynomial-time or a pseudo-polynomial-time algorithm to solve it. We also devise a fully polynomial-time approximation scheme when both agents’ scheduling criteria are the weighted number of tardy jobs.

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We study two-agent scheduling on a single sequential and compatible batching machine in which jobs in each batch are processed sequentially and compatibility means that jobs of distinct agents can be processed in a common batch. A fixed setup time is required before each batch is started. Each agent seeks to optimize some scheduling criterion that depends on the completion times of its own jobs only. We consider several scheduling problems arising from different combinations of some regular scheduling criteria, including the maximum cost (embracing lateness and makespan as its special cases), the total completion time, and the (weighted) number of tardy jobs. Our goal is to find an optimal schedule that minimizes the objective value of one agent, subject to an upper bound on the objective value of the other agent. For each problem under consideration, we provide either a polynomial-time or a pseudo-polynomial-time algorithm to solve it. We also devise a fully polynomial-time approximation scheme when both agents’ scheduling criteria are the weighted number of tardy jobs.
http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21779Satellite constellation design for forest fire monitoring via a stochastic programing approachhttp://feedproxy.google.com/~r/wileyonlinelibrary/nav/~3/m8LN2uM-bKI/doiSatellite constellation design for forest fire monitoring via a stochastic programing approachAaron B. Hoskins, Hugh R. Medal, Eghbal Rashidi2018-02-28T01:05:59.877696-05:00doi:10.1002/nav.21781John Wiley & Sons, Inc.10.1002/nav.21781http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21781RESEARCH ARTICLE642661Abstract

There is significant value in the data collected by satellites during and after a natural disaster. The current operating paradigm in practice is for satellites to passively collect data when they happen to fly over a disaster location. Conversely, this article considers the alternative approach of actively maneuvering satellites to fly directly overhead of the disaster site on a routine basis. Toward this end, we seek to compute a satellite constellation design that minimizes the expected maneuver costs for monitoring an unknown forest fire. In this article, we present a 2-stage stochastic programing model for this problem as well as a accelerated L-shaped decomposition approach. A comparison between our approach and the current operating paradigm indicates that our solution provides longer duration data collections and a greater number of data collections. Analysis also shows that our proposed solution is robust over a wide array of scenarios.

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There is significant value in the data collected by satellites during and after a natural disaster. The current operating paradigm in practice is for satellites to passively collect data when they happen to fly over a disaster location. Conversely, this article considers the alternative approach of actively maneuvering satellites to fly directly overhead of the disaster site on a routine basis. Toward this end, we seek to compute a satellite constellation design that minimizes the expected maneuver costs for monitoring an unknown forest fire. In this article, we present a 2-stage stochastic programing model for this problem as well as a accelerated L-shaped decomposition approach. A comparison between our approach and the current operating paradigm indicates that our solution provides longer duration data collections and a greater number of data collections. Analysis also shows that our proposed solution is robust over a wide array of scenarios.
http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21781Performance analysis of the cultural and creative industry: a network-based approachhttp://feedproxy.google.com/~r/wileyonlinelibrary/nav/~3/hVbX_5dKvSk/doiPerformance analysis of the cultural and creative industry: a network-based approachWen-Min Lu, Qian Long Kweh, Dong-Sing He, Jui-Min Shih2018-01-04T23:05:37.306232-05:00doi:10.1002/nav.21777John Wiley & Sons, Inc.10.1002/nav.21777http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21777RESEARCH ARTICLE662676Abstract

The cultural and creative industries (CCIs) in Taiwan have gradually contributed to the national economy under the impetus of government policies. We employ a two-stage data envelopment analysis model with an additive efficiency decomposition approach to measure the profitability and marketability of 22 Taiwanese cultural and creative companies. Furthermore, we employ the network-based ranking approach to identify benchmark inputs/outputs, and the strengths and weakness of each company. Our empirical results show that the profitability of the cultural and creative companies is better than their marketability. Companies in the industries of publishing, creative life, popular music, and cultural content averagely perform better than those in the other three types of CCIs in terms of profitability. Companies in the creative life industry are on average more efficient than those in the other five types of CCIs in terms of marketability. The profitability/marketability matrix of cultural and creative companies is also presented.

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The cultural and creative industries (CCIs) in Taiwan have gradually contributed to the national economy under the impetus of government policies. We employ a two-stage data envelopment analysis model with an additive efficiency decomposition approach to measure the profitability and marketability of 22 Taiwanese cultural and creative companies. Furthermore, we employ the network-based ranking approach to identify benchmark inputs/outputs, and the strengths and weakness of each company. Our empirical results show that the profitability of the cultural and creative companies is better than their marketability. Companies in the industries of publishing, creative life, popular music, and cultural content averagely perform better than those in the other three types of CCIs in terms of profitability. Companies in the creative life industry are on average more efficient than those in the other five types of CCIs in terms of marketability. The profitability/marketability matrix of cultural and creative companies is also presented.
http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21777Scheduling combat logistics force replenishments at sea for the US Navyhttp://feedproxy.google.com/~r/wileyonlinelibrary/nav/~3/ElYV7tqaRhw/doiScheduling combat logistics force replenishments at sea for the US NavyGerald G. Brown, Walter C. DeGrange, Wilson L. Price, Anton A. Rowe2018-02-23T11:25:38.771591-05:00doi:10.1002/nav.21780John Wiley & Sons, Inc.10.1002/nav.21780http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21780RESEARCH ARTICLE677693Abstract

The Replenishment at Sea Planner (RASP) is saving the U.S. Navy millions of dollars a year by reducing fuel consumption of its Combat Logistics Force (CLF). CLF shuttle supply ships deploy from ports to rendezvous with underway U.S. combatants and those of coalition partners. The overwhelming commodity transferred is fuel, ship-to-ship by hoses, while other important packaged goods and spare parts are high-lined, or helicoptered between ships. The U.S. Navy is organized in large areas of responsibility called numbered fleets, and within each of these a scheduler must promulgate a daily forecast of CLF shuttle operations. The operational planning horizon extends out several weeks, or as far into the future as we can forecast demand. We solve RASP with integer linear optimization and a purpose-built heuristic. RASP plans Replenishment-at-Sea (RAS) events with 4-hour (Navy watch) time fidelity. For five years, RASP has served two purposes: (1) it helps schedulers generate a daily schedule and animates it using Google Earth, and (2) it automates reports command-to-ship messages that are essential to keep this complex logistics system operating.

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The Replenishment at Sea Planner (RASP) is saving the U.S. Navy millions of dollars a year by reducing fuel consumption of its Combat Logistics Force (CLF). CLF shuttle supply ships deploy from ports to rendezvous with underway U.S. combatants and those of coalition partners. The overwhelming commodity transferred is fuel, ship-to-ship by hoses, while other important packaged goods and spare parts are high-lined, or helicoptered between ships. The U.S. Navy is organized in large areas of responsibility called numbered fleets, and within each of these a scheduler must promulgate a daily forecast of CLF shuttle operations. The operational planning horizon extends out several weeks, or as far into the future as we can forecast demand. We solve RASP with integer linear optimization and a purpose-built heuristic. RASP plans Replenishment-at-Sea (RAS) events with 4-hour (Navy watch) time fidelity. For five years, RASP has served two purposes: (1) it helps schedulers generate a daily schedule and animates it using Google Earth, and (2) it automates reports command-to-ship messages that are essential to keep this complex logistics system operating.
http://onlinelibrary.wiley.com/resolve/doi?DOI=10.1002%2Fnav.21780